Generally, display devices for notifying information, such as a telephone number, a price, a pattern, and a phrase, include a signboard, a banner, a sign, and the like. Most of the display devices use an optical method in order to improve day and night visibility. Especially, display devices having various structures using an LED have been recently suggested, and an advertising effect has been obtained through a new function of the display device.
A representative display device among the display devices using the LED includes a display device using a light guide pad, in which an advertisement phrase or a design is imprinted on a surface of the light guide pad, LED devices as light sources are mounted to a side cross-section to emit light, and the characters or the advertisement phrase or design are displayed to the outside by using the light. The light guide pad in the conventional display device is generally made of a transparent acryl material and has a flat panel-type main body. The aforementioned light guide pad using the acryl has excellent light transmission performance, so that the light is distributed and scattered in the pattern, such as the character or the design, while being incident to and guided in an inside of an acryl panel by the LED devices constituting the light sources, so as to display the corresponding character or advertisement phrase to the outside, thereby achieving an advertising effect.
However, since the conventional display device uses a planar light guide pad, all characters and designs imprinted on the light guide pad are simultaneously turned on/off according to the turning on/off of the light source, and the character or the design cannot be individually turned on/off, so that the change of the character, or the like, is impossible. Further, the conventional display device uses a thick and hard acryl panel as the light guide pad, so that there is a disadvantage in that the display device cannot be bent. Accordingly, the disadvantage causes the deterioration of applicability of the conventional display device to various fields, such as the signboard or the banner, using the light.